1. Technical Field
The present invention relates to a liquid ejecting head that ejects liquid from nozzle openings, a liquid ejecting head unit and a liquid ejecting apparatus.
2. Related Art
The liquid ejecting apparatus that is represented by an ink jet type recording apparatus such as an ink jet type recording head, a plotter or the like includes a liquid ejecting head (hereinafter, also referred to as the recording head) that can eject a liquid such as ink or the like reserved in a liquid reservoir such as a cartridge, a container or the like, as liquid droplets (ink droplets).
A serial-type liquid ejecting apparatus and a line-type liquid ejecting apparatus in practical use as the liquid ejecting apparatus wherein the serial-type liquid ejecting apparatus performs a printing by moving the liquid ejecting head in a scanning direction with respect to an recording medium that is a recording sheet or the like such as paper or the like, and the line-type liquid ejecting apparatus performs a printing by fixing the liquid ejecting head in which nozzle openings are disposed over the width of the recording medium and transporting only the recording medium (for example, see JP-A-5-16370).
However, even in either of the serial-type and the line-type liquid ejecting apparatuses, because the recording medium and the liquid ejecting head are moved relatively, air stream is generated by the relative movement and when ink is ejected from the nozzle openings, a small liquid droplet (one referred to as mist or a satellite droplet) that is separated from a main droplet (main liquid droplet) is generated, and the small liquid droplet is attached in a separate position to the main droplet on the recording medium by the flow of the air stream so that printing quality is lowered. Also, the small liquid droplet is attached to the meniscus of the liquid at the liquid openings and destroys the meniscus so that the liquid droplets cannot be ejected normally from the nozzle openings.
To solve the above-described problem, a drawing head apparatus is suggested in which a hood is disposed on a liquid ejecting surface that ejects the ink of the recording head so as to cover a vicinity of the recording medium from the nozzle openings. The drawing head apparatus suppresses that small liquid droplets are landed in the position other than the main droplet by the air stream that is generated by the relative movement of the recording medium and the recording head (for example, see JP-A-2000-62166).
However, in JP-A-2000-62166, there are problems in that if only by disposing the hood on the recording head, a turbulent air stream that is directed by the hood is inversely generated and the small liquid droplet lands in a position separate to the main droplet on the recording medium so that printing quality is lowered and destruction of the meniscus is generated.
Specifically, in a case where the relative movement of the recording head and the recording medium reaches a high velocity, and high velocity printing is performed, the above-described problems are noticeably present.
These problems are present not only in an ink jet type recording head that ejects ink but also in a liquid ejecting head that ejects liquids other than ink similarly.